Base class for any SPI slave device. More...

#include <fastarduino/spi.h>

Inheritance diagram for spi::SPIDevice< CS, CS_MODE, RATE, MODE, ORDER >:

Collaboration diagram for spi::SPIDevice< CS, CS_MODE, RATE, MODE, ORDER >:

Protected Member Functions
	SPIDevice () INLINE=default
	Create a new `SPIDevice`; this sets up the `CS` pin for later use during transfers.

void	start_transfer ()
	Start an SPI transfer to this device. More...

void	end_transfer () INLINE
	End the current SPI ransfer tot hsi device. More...

Protected Member Functions inherited from spi::AbstractSPIDevice
	AbstractSPIDevice (const AbstractSPIDevice &)=delete

AbstractSPIDevice &	operator= (const AbstractSPIDevice &)=delete

uint8_t	transfer (uint8_t data)
	Transfer one byte to the currently selected SPI slave device through MOSI pin, and get the byte returned by the device through MISO pin. More...

void	transfer (uint8_t *data, uint16_t size)
	Transfer an array of payload data to the currently selected SPI slave device through MOSI pin, and get all data bytes simultaneously received from that device through MISO pin. More...

void	transfer (const uint8_t *data, uint16_t size)
	Transfer an array of payload data to the currently selected SPI slave device through MOSI pin; any data bytes simultaneously received from that device through MISO pin are lost. More...

void	transfer (uint8_t *data, uint16_t size, uint8_t sent)
	Transfer the provided byte `sent` several times to the currently selected SPI slave device through MOSI pin, and get all data bytes simultaneously received from that device through MISO pin. More...

void	transfer (uint16_t size, uint8_t sent)
	Transfer the provided byte `sent` several times to the currently selected SPI slave device through MOSI pin; any data bytes simultaneously received from that device through MISO pin are lost. More...

Detailed Description

template<board::DigitalPin CS, ChipSelect CS_MODE = ChipSelect::ACTIVE_LOW, ClockRate RATE = ClockRate::CLOCK_DIV_4, Mode MODE = Mode::MODE_0, DataOrder ORDER = DataOrder::MSB_FIRST>
class spi::SPIDevice< CS, CS_MODE, RATE, MODE, ORDER >

Base class for any SPI slave device.

It contains the barebones API for implementing a real device.

Implementing a new SPI device consists mainly in subclassing SPIDevice and add public device-specific methods that will use start_transfer(), transfer() and end_transfer() to communicate with the actual device.

The snippet below illustrates this and summarizes the definition of an SPI based device, the Winbond W25Q80BV flash-memory chip:

template<board::DigitalPin CS>
class WinBond : public spi::SPIDevice<CS, spi::ChipSelect::ACTIVE_LOW, spi::ClockRate::CLOCK_DIV_2>
{
public:
    void write_page(uint32_t address, uint8_t* data, uint8_t size)
    {
        send(0x02, address, data, (size == 0 ? 256 : size));
    }
    uint8_t read_data(uint32_t address);
    void read_data(uint32_t address, uint8_t* data, uint16_t size);
    ...
private:
    void send(uint8_t code, uint32_t address, uint8_t* data, uint16_t size)
    {
        this->start_transfer();
        this->transfer(code);
        this->transfer(address >> 16);
        this->transfer(address >> 8);
        this->transfer(address);
        this->transfer(data, size);
        this->end_transfer();
    }
    ...
};

Template Parameters

CS	the pin used to select the slave device; this may be `DigitalPin::NONE` if your device is alone on the SPI bus, its CS pin is forced low (always active), and your device actually supports this way of working. Some devices do not like having an always-0 CS pin!
CS_MODE	the chip select active mode
RATE	the SPI clock rate for this device
MODE	the SPI mode used for this device
ORDER	the bit order for this device

Definition at line 330 of file spi.h.

Member Function Documentation

◆ start_transfer()

template<board::DigitalPin CS, ChipSelect CS_MODE = ChipSelect::ACTIVE_LOW, ClockRate RATE = ClockRate::CLOCK_DIV_4, Mode MODE = Mode::MODE_0, DataOrder ORDER = DataOrder::MSB_FIRST>

void spi::SPIDevice< CS, CS_MODE, RATE, MODE, ORDER >::start_transfer ( )

inlineprotected

Start an SPI transfer to this device.

Concretely this sets the active level on CS pin.

Definition at line 344 of file spi.h.

◆ end_transfer()

template<board::DigitalPin CS, ChipSelect CS_MODE = ChipSelect::ACTIVE_LOW, ClockRate RATE = ClockRate::CLOCK_DIV_4, Mode MODE = Mode::MODE_0, DataOrder ORDER = DataOrder::MSB_FIRST>

void spi::SPIDevice< CS, CS_MODE, RATE, MODE, ORDER >::end_transfer ( )

inlineprotected

End the current SPI ransfer tot hsi device.

Concretely this clears the active level on CS pin.

Definition at line 362 of file spi.h.

The documentation for this class was generated from the following file:

fastarduino/spi.h

Protected Member Functions

Detailed Description

Member Function Documentation

◆ start_transfer()

◆ end_transfer()